On method: the handoff statistic

Every volume of Principles of Practice ends by naming the number its field repeats most often and explaining why the book does not use it. For integrated operations, that number is the claim that around eighty percent of errors originate at handoffs.

You will find it attributed to healthcare research, to aviation, to manufacturing, and occasionally to all three in the same slide. Follow it back and it dissolves. Some versions trace to a study of clinical handovers in a single hospital with a sample in the dozens. Some trace to nothing at all. The versions with a real source measured something narrower than the claim made from them, usually communication failures among contributing factors in reviewed incidents, which is not the same as eighty percent of errors originating anywhere.

The underlying observation is almost certainly directionally right, which is what makes the number so durable. Seams really are where a disproportionate share of failure lives. But directionally right is not a measurement, and an operator who reorganises a department around a figure they cannot source has done the thing this whole course argues against.

The four questions from Volume I apply unchanged. Who produced it and what were they selling. What was the sample and of what population. What exactly was measured, in units. Has anyone independent reproduced it.

NBOP publishes what it cannot claim. This volume argues that seams are where integrated operations fails, and it argues it from mechanism rather than from a percentage, because the mechanism is checkable and the percentage is not.